Luminaire assembly designs of the prior art include a housing for enclosing and protecting electrical components required for operation of the luminaire, and an optical assembly. The optical assembly is generally comprised of a lighting unit and a refractor for producing and directing light of various intensities. These prior art designs often utilize electrical assemblies that are wired directly to the lighting unit through the use of a plurality of wires, splicing means, and/or permanent connecting means.
Direct wired electrical assemblies of the type referenced above have heretofore been used to ensure proper electrical contact between system components. Those skilled in the art will recognize, however, that such prior art designs have resulted in increased installation and maintenance costs because of the minimal flexibility afforded by the mechanical design. For example, it is known by those skilled in the art that particular system components of the luminaire assemblies of the type referenced herein often require repair, replacement and adjustment. In high pressure sodium systems, for example, starters, ballasts and capacitors are known to require routine maintenance. Similarly, the wattage and/or voltage characteristics of the employed lighting units often require adjustment to provide the proper amount of illumination and to conserve energy. These maintenance procedures often include the disassembly of sometimes heavy and awkward parts as well as the removal, splicing and reconnection of electrical wires. Because of the direct wired design of the prior art systems, these maintenance procedures must also be performed on-site or, in the alternative, the luminaire must be temporarily disabled while the particular component is repaired in the laboratory or factory.
The optical units of the prior art luminaire assemblies are also known to those skilled in the art to require routine repair, replacement and maintenance. For example, it is known that refractors and lighting units often must be replaced when the surfaces are penetrated by foreign substances or, when they have been fractured as a result of weather conditions or tampering. These time-consuming and labor intensive maintenance procedures must again be performed on-site and on a regular basis.
It is appreciated by those skilled in the art that the maintenance procedures referenced above are, of course, further hindered during adverse weather conditions, including heavy winds, rain and snow as well as extreme temperature gradients. The maintenance complications inherent in the prior art luminaire assembly designs have resulted in increased labor and maintenance costs which, in turn, have caused purchasers and luminaire designers to turn their attention toward viable design alternatives.
In addition to hindering repair and replacement of components, luminaire assemblies of the prior art suffer from a lack of flexibility in design. These designs make insufficient use of subassemblies, though it is well known that flexibility increases with proper employment of subassemblies. For example, instead of individually mounting small components such as starters, ballasts and capacitors to a lighting unit, it may be possible to instead attach them to a base or platform. This platform would comprise a subassembly which is then mounted to the lighting unit. Modified or new electrical components may then be incorporated into the platform. The platform can be modified to accept the new component inexpensively and quickly without affecting any other part of the luminaire. Creation of the most efficient number and type of subassemblies is an important object of current designers.
U.S. Pat. Nos. 3,297,864 and 3,071,683 issued to Waldbauer and Queale, respectively disclose prior art luminaire designs of the type referenced above. The Waldbauer patent for example, discloses a luminaire having a lighting unit, a refractor, and an electrical assembly mounted on a pivoting door. The system components of the Waldbauer luminaire are directly wired to the lighting unit.
Similarly, the Queale patent discloses a luminaire having a lighting unit, a refractor, and an electrical assembly wherein the luminaire is pivotably affixed to the luminaire housing at one end. Again, the electrical components are directly wired to the lighting unit and thus require maintenance on-site.